The United States and Mongolia are bolstering military ties under a deal signed in Ulan Bator by Pentagon chief Chuck Hagel.
The Mongolian capital is the last stop on the defense secretary's 10-day Asia tour, which has also included visits in China and Japan.
Under the "joint vision statement" signed Thursday, the United States will provide expanded military training and assistance to Mongolia.
The U.S. currently provides about $3 million in military sales and training to the Asian country, which borders China and Russia.
Hagel's stop included visits with senior Mongolian officials, as well as soldiers who have served alongside U.S. troops in Iraq and Afghanistan.
The defense secretary arrived in Ulan Bator from Beijing, where he met Wednesday with Chinese President Xi Jinping.
Both leaders focused their public remarks on developing warmer U.S.-China relations, unlike Hagel's previous comments in Beijing.
Throughout the three-day stop, Hagel called on Beijing to lessen tension with its neighbors and be more transparent about its military strength.
Specifically, he renewed U.S. criticism of the air defense identification zone set up by China last year that covers islands claimed by Tokyo.
He also said the United States is committed to fulfilling its treaty obligations to defend Japan and the Philippines in the case of any conflict with China.
Hagel's Chinese counterpart, Chang Wangquan, stood firm, vowing Beijing will make no compromise on the territorial disputes.
Japan and the Philippines are among several Asian countries that accuse China of using intimidation to advance its maritime claims.
Many countries have strengthened military ties with the United States as a result, leading China to complain Washington is trying to contain its rise.
U.S. officials dispute the claim, saying the White House's renewed Asian focus is aimed at protecting international law and freedom of navigation.